Cosmetic compositions are used by consumers for regulating the condition of the skin and/or for improving the appearance of the skin. Cosmetic compositions, such as foundations, are popular amongst consumers, because they are capable of masking skin imperfections and skin tonal, variations—this ability is referred to as “coverage.” These compositions also may provide coloration to the skin by incorporating conventional metal oxide pigments into the compositions, such as iron oxide pigments and titanium dioxide and other powder. Cosmetic compositions also are popular amongst consumers, because they are capable of correcting skin discoloration.
Depending on the consumers' taste and/or the degree of skin imperfections and/or the skin tonal variations and/or the skin discoloration surrounding the eyes, a high coverage effect may be desired and/or needed. A high coverage effect may be obtained by incorporating a high proportion of pigments, especially pigmentary grade titanium dioxide particles, into the cosmetic compositions. Application onto the skin of a composition providing high coverage, however, usually impairs the natural appearance of the skin. In particular, the application onto the skin of a composition providing high coverage usually results in a white hue across the skin. The white hue is also known as “chalkiness” for consumers having darker skins and “pastiness” for consumers having lighter skins. There is a need, therefore, to provide a cosmetic composition providing high coverage, particularly for masking skin imperfections and/or tonal variations of the skin, while retaining a natural skin appearance. There also is a need to provide a cosmetic composition correcting the skin discoloration surrounding the eyes, while retaining a natural skin appearance. There also is a need to provide a cosmetic composition which delivers high coverage whilst imparting a minimal white hue (ghost-like, doll-like effect) to the skin, or even whilst imparting no white hue to the skin. There also is a need to provide a cosmetic composition which delivers high coverage to darker skin whilst imparting minimal chalkiness, or even whilst imparting no chalkiness. There also is a need to provide a cosmetic composition which delivers high coverage to lighter skin whilst imparting minimal pastiness, or even whilst imparting no pastiness. Finally, there is a need to provide a cosmetic composition that delivers high coverage to the skin, and that minimizes further the white hue to the skin, compared to currently marketed cosmetic compositions.
Chalkiness and/or pastiness, i.e. the white hue across the skin, and more generally an unnatural appearance of the skin, is generally associated with the reflectance angle of light. When using conventional titanium dioxide, there is a specular reflection observed. This undesirable effect may be reduced by incorporating a lower proportion of pigmentary grade titanium dioxide particles into the cosmetic compositions, but doing that has the disadvantage of reducing the coverage provided to the skin. There is a need, therefore, to provide a cosmetic composition that provides high coverage of skin while minimizing the specular reflection.
The use of aluminum hydroxide powder in cosmetic compositions is known. Typically, the compositions include aluminum hydroxide deposited on the surface of a powder as a coating, as described for example, in U.S. Pat. Nos. 4,084,983, 4,323,554, 4,309,480, 4,968,351, 5,156,889, 6,416,573, 6,531,524, 6,630,019, 7,531,184, and U.S. Patent Application Publication No. 2001/0005735, the disclosures of each of which are incorporated by reference herein in their entireties. It also has been known to use alumina, not aluminum hydroxide, as a powder particle, and coat the alumina at least partially with titanium dioxide (JP 2008-088317), or phosphoric acid or phosphate (U.S. Pat. No. 6,015,456). It also has been described in U.S. Pat. No. 7,682,604 to provide a composite powder useful in cosmetic compositions in which a flaky substrate powder (e.g., mica) is contacted with a seed particle that acts as nuclei on the surface of the flaky substrate to grow barium sulfate particles or zinc oxide particles. Seed particles include titanium oxide, zinc oxide, alumina, aluminum hydroxide, silica, and iron oxide.
Accordingly, what is needed in the art is a pigment that can be used in cosmetic systems without using a significant amount of emulsifiers.